virtual machines

Introduction to Virtualization

Wikipedia says that “Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources.”

Here, the context mainly will be OS virtualization. The three basic layers of a Virtual System are :

Guest System – The system that the user sees

HyperVisor ( VMM or Virtualization Layer in general) – The enabler of virtualization which is generally a software

Host system- The machine on which we host the VMM so as to enable it to host a guest system.

Hypervisors or Virtual Machine Managers

There are two types of Hypervisors – Type 1 and Type 2. Type 1 hypervisors are VMMs which directly interact with the Hardware of the Host and don’t have any mediator in between. Example is Citrix XEN. Type 2 hypervisors are the ones that are pure software and work indirectly with the hardware via a host Operating System. Example – Parallels for Mac. (Don’t be confused between these n Software/Hardware Virtualization)

Has three parts :

Dispatcher – Routes Instructions to the Hardware

Allocator – Allocates resources to the VM

Interpreter – Interprets the instructions and does whatever’s necessary